High-speed-cutting-tool alloy.



UNITED STATES PATENT OFFICE.

GEORGE L. KELLEY, OF GERMANTOWN, AND ALBERT E MILLER, OF AMIBLER, PENN SYL- VANIA, ASSIGNORS TO .THE MIDVALE STEEL COMPANY, OF PHILADELPHIA, PENN- SYLVANIA,'A CORPORATION OF PENNSYLVANIA.

HIGH-SPEED-GUTTING-TOOL ALLOY.

No Drawing.

To all whom it may concern:

Be it known that we, GEORGE L. KELLEY and ALBERT H. MILLER, citizens of the United States, residing at Germantown, county of Philadelphia, and State of Pennsylvania, and Ambler, county of Montgomery, and State of Pennsylvania, respectively, have invented a new and useful Improvement in High-Speed-Cutting-Tool Alloys, of which the following is a full, clear, and exact description. y

The object of our invention is to provide an alloy suitable for use in the manufacture of high speed cutting tools, and which, 1n addition to having in normal degree the qualities required for such tools, will g1ve them in an especial degree the quality of toughness.

The use of zirconium as an element of such an alloy has heretofore been known and its use, associated with a preponderating amount of nickel or cobalt, has been" recommended in proportions varying from two to forty per cent. We have found, however, that a superior product may be obtained if the quantity of zirconium be reduced to below what has heretofore been considered the minimum of efiiciency provided there are associated with the zirconium aluminum and silicon in certain minimum proportions substantially exceeding the proportion of zirconium.

The composition which we prefer comprises the following ingredients in the pro-. portions specified:

Carbon .1 per cent. Nickel 86.4 Aluminum 6. Silicon 6. Zirconium 1.5

Corresponding proportions of the abdve ingredients, or part of the nickel alone, may be displaced by tungsten, which may be added in proportions varying from 1 to 10 per-cent.

The zirconium may yary from .5 to 2 per cent. A larger proportion of zirconium is not prohibitive, but Where silicon and aluminum are present in the required proportions, an excess of'zirconiumis without Specification of Letters Patent.

Patented Mar. 5, 1918.

Application filed June 26, 1917. Serial No. 177,053.

portions of each may range from 2 to 8 per cent. If, however, either the aluminum or silicon is reduced to ,(say) two per cent. it is preferred not to reduce theproportion of the other. Thus, we have found that 2 per cent. of silicon and 6 per cent. of aluminum give substantially the same qualities as 2 per cent. of aluminum and 6 per cent. ofsilicon. VVhile, therefore, it would seem that these two metals are substantial equivalents, this is found not to be actually the case, because an entire elimination of either metal and its entire replacement by the other produce an alloythat is notably inferior.

While we find that our improvedalloy is especially adapted to the manufacture of high speed cutting tools, we do not intend to confine ourselves to this particular use,

- containing a preponderating amount of nickel, zirconium one-half to two per cent.,

and an amount of aluminum and silicon at least double the amount of zirconium.

'2. An alloy for high speed cutting tools containing a preponderating amount of nickel, zirconium one-half to two per cent, and aluminum and silicon each of the last two metals constitutingfrom 2 to 8 per cent. of the alloy.

3. An alloy for high speed cutting tools containing a preponderating amount of nickel, zirconium not less than .05 er cent., and from 8 to 16 per cent. of alummum and silicon.

In testimony of which invention we have hereunto set our hands at Philadelphia, on this 22d day of June, 1917. I

t G. L. KELLEY.

A. H. MILLER. 

